Antimicrobial Resistance of Campylobacter jejuni, Escherichia coli and Enterococcus faecalis Commensal Isolates from Laying Hen Farms in Spain

Oregano Essential Oil and Purple Garlic Powder Effects on Intestinal Health, Microbiota Indicators and Antimicrobial Resistance as Feed Additives in Weaning Piglets

Finding alternatives to zinc oxide is a pressing issue for the pig production sector. We studied the impact of the bioactive components degradation of oregano essential oil (OEO) and purple garlic powder (PGP) during storage in silos, their effect on the morphometry of the jejunum and ileum and the cecal microbiota as intestinal health indicators in piglets during the post-weaning period. We also monitored antimicrobial resistance in the commensal indicator E. coli. Histological parameters and intestinal microbiota were measured in 140 piglets weaned at 21 days of age. Seven dietary treatments were used: a negative control group (basal diet), a positive control group with ZnO (3000 mg/kg of food), two groups with OEO at 0.4% and 1.2%, respectively, two groups with PGP 0.4% and 2%, respectively, and a group with OEO with 1.2% combined with PGP with 2%. Each group of piglets received the treatment for seven weeks, from weaning, before samples were taken. Antibiotic resistance profiles were measured in 81 E. coli strains. On this occasion, only the control groups, ZnO, OEO 1.2%, PGP 2% and OEO 1.2% + PGP 2% were used, and the samples were obtained from the cecal content. A progressive loss of the bioactive components of OEO and PGP was observed during the 34 days of storage (p < 0.05). PGP 2%, OEO 1.2% and their combination showed results similar to ZnO (p > 0.05), or superior in the study of intestinal morphometry and the values of E. coli and Lactobacillus. All categories showed high levels of resistance. Only the strains isolated from the OEO 1.2% group did not show resistance to colistin and presented the lowest resistance values. In general, high doses of the additives studied showed the best results, obtaining levels like or higher than those offered by ZnO.

Occurrence of Campylobacter spp. and Phenotypic Antimicrobial Resistance Profiles of Campylobacter jejuni in Slaughtered Broiler Chickens in North-Western Romania

Campylobacteriosis is recognized as one of the most common food-borne zoonoses, with worldwide distribution, having undercooked poultry meat and other cross-contaminated foodstuffs as the main sources of human infections. The current study aimed to provide data on the occurrence of the thermophilic Campylobacter spp. in seven broiler chicken flocks, from three north-western Transylvanian counties of Romania, as well as to determine the antimicrobial resistance profile of the isolated C. jejuni strains. A total of 324 fresh cecal samples were collected during the slaughtering process, and screened for the presence of Campylobacter spp., using routine microbiological and molecular diagnostic tools. Overall, 85.2% (276/324; 95% CI 80.9-88.6) of the tested samples expressed positive results for Campylobacter spp., with dominant occurrence of C. coli towards C. jejuni (63.4% vs. 36.6%). From the six tested antimicrobials, the 101 isolated C. jejuni strains were resistant against ciprofloxacin (79.2%), nalidixic acid (78.2%), tetracycline (49.5%), and streptomycin (7.9%), but total susceptibility was noticed against erythromycin and gentamicin. Seven (6.9%) isolates exhibited multidrug resistance. The study results emphasize the role of broiler chicken as reservoir of Campylobacter infections for humans, as well as strengthen the necessity of the prudent using of antimicrobials in the poultry industry.

Prevalence and Antimicrobial Resistance of Campylobacter jejuni and Campylobacter coli from Laying Hens Housed in Different Rearing Systems

Campylobacter (C.) jejuni and C. coli are responsible for food poisoning in humans. Laying hens may host the bacteria usually without developing symptoms. The aims of this paper were to evaluate the incidence of C. jejuni and C. coli infection in laying hen flocks housed in different rearing systems, the plasma levels of two welfare indicators (corticosterone and interleukin 6, IL-6) and the antimicrobial resistance of the detected Campylobacter strains. Two different flocks (1 and 2) from cage (A), barn (B) and aviary (C) farms were investigated. The highest (p < 0.05) levels of IL-6 were detected in laying hens housed in aviaries. A similar trend emerged in corticosterone level, although differences were found between C1 and C2. C. jejuni and C. coli were identified in 43.5% and 38.9% of birds, respectively. In total, 14 out of 177 (7.9%) hens simultaneously hosted C. jejuni and C. coli.C. jejuni was prevalently detected in hens housed in barns (B1: 53.3%; B2: 46.7%) and aviaries (C1: 34.6%; C2: 86.7%). Conversely, laying hens housed in cages were significantly exposed to infection of C. coli (A1: 41.9%; A2: 80%) while, regarding barns and aviaries, a significant prevalence emerged only in flocks B2 (40%) and C1 (54.8%). Simultaneous infection was statistically significant in barn B1 (36.7%). Antibiotic resistance was mainly detected among C. coli strains, and it was most frequent for fluoroquinolones and tetracycline. Multidrug resistance was also found in C. jejuni (19.7%) and C. coli (17.5%) strains. Based on the results of this study, we recommend increasing biosecurity and hygienic measures to manage hen flocks.

Antimicrobial Resistance Trends of Escherichia coli Isolates: A Three-Year Prospective Study of Poultry Production in Spain

Antimicrobial resistance (AMR) poses a major threat to health worldwide. Poultry products are one of the main threats, due to the transmission of antimicrobial resistance genes throughout the food chain. Escherichia coli is the main cause of mortality in the poultry industry, mainly mitigated with antibiotics, but due to the high genetic strain variability, recurrent outbreaks of multidrug resistant E. coli take place. The major challenge to tackling AMR is understanding the burden of resistance. For this reason, one of the main strategies is monitoring AMR by phenotypic characterisation. Our study aimed to monitor the resistance of E. coli strains isolated from the poultry sector over a period of three years (2019–2021) to provide information on the resistance magnitude and trends. Promising results have been found concerning the low frequency of resistance to cephalosporins, polymyxin, and fluoroquinolones. However, levels of resistance found to antimicrobials such as erythromycin (100%), tylosin (98%), or penicillin (97%) suggest the need to continue working on the limitation of use of antimicrobials in poultry to achieve the demise of MDR.